This paper investigates the distributed Kalman filter (DKF) for linear systems, with specific attention on measurement fusion, which is a typical way of information sharing and is vital for enhancing stability and imp...
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Transparent Ce:lutetium aluminum garnet(Ce:Lu_(3)A_(l5)O_(12),Ce:LuAG)ceramics have been regarded as potential scintillator materials due to their relatively high density and atomic number(Zeff).However,the current Ce...
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Transparent Ce:lutetium aluminum garnet(Ce:Lu_(3)A_(l5)O_(12),Ce:LuAG)ceramics have been regarded as potential scintillator materials due to their relatively high density and atomic number(Zeff).However,the current Ce:LuAG ceramics exhibit a light yield much lower than the expected theoretical value due to the inevitable presence of LuAl antisite defects at high sintering *** work demonstrates a low-temperature(1100℃)synthetic strategy for elaborating transparent LuAG–Al_(2)O_(3) nanoceramics through the crystallization of 72 mol%Al_(2)O_(3)–28 mol%Lu_(2)O_(3)(ALu28)bulk *** biphasic nanostructure composed of LuAG and Al_(2)O_(3) nanocrystals makes up the whole ceramic *** of Al_(2)O_(3) is distributed among LuAG grains,and the rest is present inside the LuAG *** dense biphasic LuAG–Al_(2)O_(3) nanoceramics are highly transparent from the visible region to mid-infrared(MIR)region,and particularly the transmittance reaches 82%at 780 ***,LuAl antisite defect-related centers are completely undetectable in X-ray excited luminescence(XEL)spectra of Ce:LuAG–Al_(2)O_(3) nanoceramics with 0.3–1.0 at%*** light yield of 0.3 at%Ce:LuAG–Al_(2)O_(3) nanoceramics is estimated to be 20,000 ph/MeV with short 1μs shaping time,which is far superior to that of commercial Bi_(4)Ge_(3)O_(12)(BGO)single *** results show that a low-temperature glass crystallization route provides an alternative approach for eliminating the antisite defects in LuAG-based ceramics,and is promising to produce garnet-based ceramic materials with excellent properties,thereby meeting the demands of advanced scintillation applications.
TiNi alloys with high content Ni(52-55 at.%)are perfectly suitable for preparing wear-and corrosionresistant parts that service on the space station,spacecraft,and submarine,because of their superior superelasticity,h...
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TiNi alloys with high content Ni(52-55 at.%)are perfectly suitable for preparing wear-and corrosionresistant parts that service on the space station,spacecraft,and submarine,because of their superior superelasticity,high strength,and ***,the fabrication of complicated Ni-rich TiNi parts by the traditional machining method often faces problems of poor precision,low efficiency,and high *** this work,we succeed in preparing an excellent Ti_(47)Ni_(53) alloy by selective laser melting(SLM),and thus,open a new way for the efficient and precise formation of complicated Ni-rich TiNi parts with superelasticity and *** optimized processing window for compact parts without defects is *** elaborately fabricated Ti_(47)Ni_(53) alloy exhibited a breaking strain of 11%,a breaking stress of 2.0 GPa,a superelastic strain of 9%,and a better hardwearing than that of casting and quenched Ti_(47)Ni_(53) ***,the microstructure,phase transformation,and deformation,as well as their influence mechanisms are investigated by in situ transmission electron microscope(TEM)and high-energy X-ray diffraction(HE-XRD).The results obtained are of significance for both fundamental research and technological applications of SLM-fabricated high Ni content TiNi alloys.
Cyber-physical systems (CPSs) are designed to in-tegrate computation and physical processes through constantly interacting with the physical environment. The complexity and uncertainty of the environment often come up...
Cyber-physical systems (CPSs) are designed to in-tegrate computation and physical processes through constantly interacting with the physical environment. The complexity and uncertainty of the environment often come up with unpredictable situations, which place high demands on the dynamic adaptability of CPSs. Further, as the environment evolves, the CPS needs to constantly evolve itself to adapt to the changing environment. This paper presents a research plan that aims to develop a novel framework to address CPS design challenges under uncertain environments. We propose to utilize evolutionary computation and reinforcement learning techniques to design control policies that can adapt to the dynamic changes and uncertainties of the environment. Further, novel testing and evaluation approaches that can generate test cases while adapting to dynamic changes in the system and the environment will be explored.
In this paper the distributed asymptotic consensus problem is addressed for a group of high-order nonaffine agents with uncertain dynamics,nonvanishing disturbances and unknown control directions under directed networ...
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In this paper the distributed asymptotic consensus problem is addressed for a group of high-order nonaffine agents with uncertain dynamics,nonvanishing disturbances and unknown control directions under directed networks.A class of auxiliary variables are first introduced which forms second-order filters and induces all measurable signals of agents’*** view of this property,a distributed robust integral of the sign of the error(DRISE)design combined with the Nussbaum-type function is presented that guarantees not only the desired asymptotic consensus,but also the uniform boundedness of all closed-loop *** with the traditional sliding mode control(SMC)technique,the main feature of our approach is that the integral operation in the proposed control algorithm is designed to be adopted in a continuous manner and ensures less chattering *** results for a group of Duffing-Holmes chaotic systems are employed to verify our theoretical analysis.
In this study, we investigate the control problem of electronic throttle systems in the presence of practical challenges such as disturbances and measurement noises. To address these challenges, we propose an adaptive...
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This paper focuses on an adaptive fixed-time tracking control problem for nonstrict-feedback stochastic nonlinear systems with unknown control coefficients and output constraints. To overcome this problem, this articl...
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We have seen rapid development of autonomous driving systems (ADSs) in recent years. These systems place high requirements on safety and reliability for their mass adoption, and ADS testing is one of the crucial appro...
We have seen rapid development of autonomous driving systems (ADSs) in recent years. These systems place high requirements on safety and reliability for their mass adoption, and ADS testing is one of the crucial approaches to ensure the success of ADSs. To this end, this paper presents RLTester, a novel ADS testing approach, which adopts reinforcement learning (RL) to learn critical environment configurations (i.e., test scenarios) of the operating environment of ADSs that could reveal their unsafe behaviors. To generate diverse and critical test scenarios, we defined 142 environment configuration actions, and adopted the Time- To-Collision metric to construct the reward function. Our evaluation shows that RLTester discovered a total of 256 collisions, of which 192 are unique collisions, and took on average 11.59 seconds for each collision. Further, RLTester is effective in generating more diverse test scenarios compared to a state-of-the art approach, DeepCollision.
Rapidly increasing plastics have been used and finally become wastes,resulting in increasing pressures to the ***-assisted pyrolysis is a promising technology for converting organic wastes as waste plastics into value...
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Rapidly increasing plastics have been used and finally become wastes,resulting in increasing pressures to the ***-assisted pyrolysis is a promising technology for converting organic wastes as waste plastics into value-added *** present,many works on microwave-assisted pyrolysis of plastics have been published,but the achievements,challenges,and future directions of microwave-assisted pyrolysis of waste plastics have not been well summarized and *** this work,the principle of microwave-assisted pyrolysis technology is ***,the progress of its application to recover useful products from plastics is reviewed and discussed in terms of key parameters including microwave power,pyrolysis temperature,reaction time,types of catalyst,microwave absorbents and feedstock mixing ***,the yields and properties of the produced oil,gas and char are correlated with the process ***,the existing challenges and prospects of disposal/reuse of waste plastics by microwave-assisted pyrolysis technology are discussed.
In the era of big data,there is an urgent need to establish data trading markets for effectively releasing the tremendous value of the drastically explosive *** security and data pricing,however,are still widely regar...
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In the era of big data,there is an urgent need to establish data trading markets for effectively releasing the tremendous value of the drastically explosive *** security and data pricing,however,are still widely regarded as major challenges in this respect,which motivate this research on the novel multi-blockchain based framework for data trading markets and their associated pricing *** this context,data recording and trading are conducted separately within two separate blockchains:the data blockchain(DChain) and the value blockchain(VChain).This enables the establishment of two-layer data trading markets to manage initial data trading in the primary market and subsequent data resales in the secondary ***,pricing mechanisms are then proposed to protect these markets against strategic trading behaviors and balance the payoffs of both suppliers and ***,in regular data trading on VChain-S2D,two auction models are employed according to the demand scale,for dealing with users’ strategic *** incentive-compatible Vickrey-Clarke-Groves(VCG)model is deployed to the low-demand trading scenario,while the nearly incentive-compatible monopolistic price(MP) model is utilized for the high-demand trading *** temporary data trading on VChain-D2S,a reverse auction mechanism namely two-stage obscure selection(TSOS) is designed to regulate both suppliers’ quoting and users’ valuation ***,experiments are carried out to demonstrate the strength of this research in enhancing data security and trading efficiency.
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